Display refrigerators and freezers

ABSTRACT

A display refrigerator or freezer comprises a refrigerated storage space. Air in the refrigerated storage space is separated from air exterior to the display refrigerator or freezer by an air curtain established by one or more fans which blow air towards one or more air outlets via a cooling heat exchanger and which recover air in the air curtain via one or more air inlets for recirculation to the one or more air outlets. The refrigerated storage space has a base shelf. One or more air inlet ducts are arranged between the one or more air inlets and the one or more fans such that the air recovered via the one or more air inlets is directed by the one or more air inlet ducts towards the one or more fans. The one or more air inlet ducts, in combination with at least a portion of the base shelf, define at least a portion of a cavity beneath the base shelf, the cavity being sealed from the air recovered via the one or more air inlet.

The invention relates to display refrigerators and freezers which caneither have doors comprising transparent windows or have an open front(i.e. do not include a door). The invention also relates to methods ofand kits for modifying such display refrigerators and freezers.

Display refrigerators and freezers are commonly used in retailenvironments, such as supermarkets, to store and display products, suchas meat and dairy products, which must be kept at lower than ambienttemperatures. The open/transparent front of such refrigerators andfreezers makes it easy for customers to view the products beingdisplayed.

Display refrigerators and freezers have an air curtain, which isestablished by blowing cold air across the front of the refrigerator orfreezer. The air curtain issues from an air outlet at the top of therefrigerator or freezer towards an air inlet at the bottom of therefrigerator or freezer. The air inlet recovers air from the air curtainand recirculates it to the air outlet via a cooling heat exchanger andfan.

One problem with this type of refrigerator or freezer is that some ofthe warm air (i.e. air that is warmer than the refrigerated interior)drawn into the air inlet by the fan tends to dwell under the base shelfof the refrigerator or freezer instead of passing through to the heatexchanger. This causes warming of the underside of the base shelf. Heatsubsequently conducts through the base shelf creating “hot-spots” whichcan warm food products on the shelf. To combat this problem,refrigerator/freezer manufacturers typically increase the cooling effectprovided to the entire refrigerator or freezer, which increases energyconsumption.

A further inefficiency associated with this type of refrigerator orfreezer is that the air passing into the fan is usually turbulent anduneven. This results in air passing through only some of the heatexchanger, which reduces the efficiency of the refrigerator or freezer,again increasing energy consumption.

Display refrigerators sometimes include insulation on the underside ofthe base shelf. However, this insulation is usually provided at the rearof the refrigerator, above the cooling heat exchanger (evaporator), anddoes not prevent warm air from transferring heat into the refrigeratorat the front of the base shelf.

Rather, this insulation is typically provided to prevent freezing ofproducts at the rear of the base shelf, which can occur due to thecoldness of the cooling heat exchanger (evaporator) underneath the rearof the base shelf.

Accordingly, there is a need in the art to increase the energyefficiency of refrigerators and freezers of this type.

In accordance with a first aspect of the invention, there is provided adisplay refrigerator or freezer comprising a refrigerated storage space,air in the refrigerated storage space being separated from air exteriorto the display refrigerator or freezer by an air curtain established byone or more fans which blow air towards one or more air outlets via acooling heat exchanger and which recover air in the air curtain via oneor more air inlets for recirculation to the one or more air outlets, therefrigerated storage space having a base shelf; one or more air inletducts arranged between the one or more air inlets and the one or morefans such that the air recovered via the one or more air inlets isdirected by the one or more air inlet ducts towards the one or morefans; wherein the one or more air inlet ducts, in combination with atleast a portion of the base shelf, define at least a portion of a cavitybeneath the base shelf, the cavity being sealed from the air recoveredvia the one or more air inlets.

The display refrigerator or freezer can be a display refrigerator orfreezer comprising an interior space and a door, wherein the doorcomprises a transparent window and separates the interior space from airexternal to the display refrigerator or freezer. For example, thedisplay refrigerator or freezer can be a full glass door freezer.Alternatively, the display refrigerator or freezer can be a displayrefrigerator which is open at the front (i.e. does not have a door). Thecooling heat exchanger may be situated at the base of the displayrefrigerator or freezer or at the rear of the display refrigerator orfreezer.

The provision of the air inlet ducts of the first aspect of theinvention achieves at least two technical effects. Firstly, the airinlet ducts seal a cavity underneath the base shelf, ensuring that thewarm air recovered via the one or more air inlets cannot dwell againstthe underside of the base shelf, which reduces heat transfer from thewarm air to the base shelf and then to the food products. This allowsrefrigerator/freezer manufacturers to reduce the cooling effect providedto the entire refrigerator or freezer, and thus reduce energyconsumption. Further, the air inlet ducts provide a direct and evenchannel for air to pass through to the fans. This reduces turbulence andmakes the airflow through the fans more even, making the refrigerator orfreezer more efficient.

In some embodiments, the display refrigerator or freezer includes thesame number of air inlet ducts and fans and each air inlet duct isarranged to direct air towards a respective fan only (for example, thedisplay refrigerator or freezer may include a single air inlet duct anda single fan, and the single air inlet duct directs air towards thesingle fan). This may result in a particularly even airflow through thefans.

In some embodiments, the cavity is evacuated (i.e. contains a vacuum).In other embodiments, the cavity contains air. It has been found thatboth a vacuum and air are more effective at insulating the base shelffrom the warm air entering through the air inlet than insulationmaterial such as fibreglass or mineral wool or polyurethane foam. Insome embodiments, insulation material such as fibreglass or mineral woolor polyurethane foam may be provided under a portion of the base shelf(in the cavity and/or outside the cavity).

In some embodiments, the display refrigerator or freezer furthercomprises one or more outlet ducts arranged between the one or more fansand the cooling heat exchanger such that air blown by the one or morefans is directed towards the cooling heat exchanger. In someembodiments, the cavity is defined at least in part by a portion of theone or more outlet ducts. The addition of an outlet duct provides thefunction of a) providing a more even distribution of air over thecooling heat exchanger (e.g. evaporator), increasing efficiency; andoptionally b) forming, in part, the cavity which insulates the front ofthe base shelf from warm air entering from the air inlet.

In some embodiments, the cavity is defined (for example defined in itsentirety) by a) a combination of the base shelf and the one or more airinlet ducts; b) a combination of the base shelf, one or more air inletducts and one or more outlet ducts; c) a combination of the base shelf,one or more air inlet ducts and insulation material; d) a combination ofthe base shelf, one or more air inlet ducts, one or more outlet ductsand insulation material; or e) a combination of the base shelf, one ormore air inlet ducts and one or both of the side walls of the fridge.

In some embodiments, a sealant (for example a silicone sealant) isprovided to seal the cavity. This has the advantage that the insulationeffect provided by the cavity is maximised because warm air cannot enterthe cavity at all. It should be understood that even without a sealant,only minimal amounts of warm air can enter the cavity, which would stillbe effective in preventing warming of the underside of the base shelf.

In accordance with a second aspect of the invention, there is provided akit for retrofitting one or more air inlet ducts to a displayrefrigerator or freezer, wherein the display refrigerator or freezercomprises a refrigerated storage space, air in the refrigerated storagespace being separated from air exterior to the display refrigerator orfreezer by an air curtain established by one or more fans which blow airtowards one or more air outlets via a cooling heat exchanger and whichrecover air in the air curtain via one or more air inlets forrecirculation to the one or more air outlets, the refrigerated storagespace having a base shelf; the kit comprising one or more air inletducts for directing air recovered by the one or more air inlets towardsthe one or more fans; wherein the one or more air inlet ducts are shapedto terminate at the one or more air inlets at a first end, such that oninstallation, in combination with at least a portion of the base shelfof the refrigerator, the one or more air inlet ducts form at least aportion of a cavity beneath the base shelf, the cavity being sealed fromair recovered via the one or more air inlets.

In some embodiments, the one or more air inlet ducts are shaped toterminate at the one or more fans at a second end. This may improve airflow to the fans.

In accordance with a third aspect of the invention, there is provided adisplay refrigerator or freezer comprising: a refrigerated storagespace, air in the refrigerated storage space being separated from airexterior to the display refrigerator or freezer by an air curtainestablished by one or more fans which blow air towards one or more airoutlets via a cooling heat exchanger and which recover air in the aircurtain via one or more air inlets for recirculation to the one or moreair outlets; one or more outlet ducts arranged between the one or morefans and the cooling heat exchanger such that air blown by the one ormore fans is directed towards the cooling heat exchanger.

The outlet duct provides a more even distribution of air over thecooling heat exchanger (e.g. evaporator).

In some embodiments, the display refrigerator or freezer includes thesame number of outlet ducts and fans, wherein each outlet duct isarranged to direct air from a respective fan only (for example, thedisplay refrigerator or freezer may include a single outlet duct and asingle fan, and the single outlet duct directs air from the single fan).This may result in a particularly even airflow from the fan or fans.

In accordance with a fourth aspect of the invention, there is provided amethod of modifying a display refrigerator or freezer, wherein thedisplay refrigerator or freezer comprises a refrigerated storage space,air in the refrigerated storage space being separated from air exteriorto the display refrigerator or freezer by an air curtain established byone or more fans which blow air towards one or more air outlets via acooling heat exchanger and which recover air in the air curtain via oneor more air inlets for recirculation to the one or more air outlets, therefrigerated storage space having a base shelf; the method comprising:arranging one or more air inlet ducts between the one or more air inletsand the one or more fans such that the air recovered via the one or moreair inlets is directed by the one or more air inlet ducts towards theone or more fans such that the one or more air inlet ducts, incombination with at least a portion of the base shelf, define at least aportion of a cavity beneath the base shelf, the cavity being sealed fromthe air recovered via the one or more air inlets.

In some embodiments, the method comprises arranging the same number ofair inlet ducts between the air inlet or inlets and the fans as thenumber of fans, such that each air inlet duct is arranged to direct aironto a respective fan only. (For example, the method may comprisearranging only one air inlet duct between the air inlet(s) and the fan,if the display refrigerator or freezer comprises only a single fan).This may result in a particularly even airflow through the fans.

In some embodiments, the method further comprises evacuating the cavity.In other embodiments, the method comprises allowing the cavity to befilled with air. It has been found that both a vacuum and air are moreeffective at insulating the base shelf from the warm air enteringthrough the air inlet(s) than insulation material.

In some embodiments, the method further comprises arranging one or moreoutlet ducts between the one or more fans and the cooling heat exchangersuch that air blown by the one or more fans is directed towards thecooling heat exchanger. The one or more outlet ducts may be arrangedsuch that the cavity is defined at least in part by a portion of one ormore outlet ducts. The addition of one or more outlet ducts provides thefunction of a) providing a more even distribution of air over thecooling heat exchanger (e.g. evaporator), increasing efficiency andoptionally b) forming, in part, the cavity which insulates the front ofthe base shelf from warm air entering from the air inlet.

In some embodiments, the method comprises arranging the one or more airinlet ducts and optionally the one or more outlet ducts and/orinsulation material such that the cavity is defined (for example definedin its entirety) by a) a combination of the base shelf and the one ormore air inlet ducts; b) a combination of the base shelf, one or moreair inlet ducts and one or more outlet ducts; c) a combination of thebase shelf, one or more air inlet ducts and insulation material; d) acombination of the base shelf, one or more air inlet ducts, one or moreoutlet ducts and insulation material; or e) a combination of the baseshelf, one or more air inlet ducts and one or both of the side walls ofthe fridge.

In some embodiments, the method comprises providing a sealant (forexample a silicone sealant) to seal the cavity. This has the advantagethat the insulation effect provided by the cavity is maximised becausewarm air cannot enter the cavity at all. It should be understood thateven without a sealant, only minimal amounts of warm air can enter thecavity, which would still be effective in preventing warming of theunderside of the base shelf.

In accordance with a fifth aspect of the invention, there is provided amethod of modifying a display refrigerator or freezer, wherein thedisplay refrigerator or freezer comprises a refrigerated storage space,air in the refrigerated storage space being separated from air exteriorto the display refrigerator or freezer by an air curtain established byone or more fans which blow air towards one or more air outlets via acooling heat exchanger and which recover air in the air curtain via oneor more air inlets for recirculation to the one or more air outlets, themethod comprising arranging one or more outlet ducts between the one ormore fans and the cooling heat exchanger such that air blown by the oneor more fans is directed towards the cooling heat exchanger.

In some embodiments, the method comprises arranging the same number ofoutlet ducts between the fans and the cooling heat exchanger as thenumber of fans, such that each outlet duct is arranged to direct airfrom a respective fan only. For example, where the display refrigeratoror freezer includes only a single fan, a single outlet duct may bearranged between the said fan and the cooling heat exchanger. This mayresult in a particularly even airflow from the fans.

In accordance with a sixth aspect of the invention, there is provided akit for retrofitting one or more outlet ducts to a display refrigeratoror freezer, wherein the display refrigerator or freezer comprises arefrigerated storage space, air in the refrigerated storage space beingseparated from air exterior to the display refrigerator or freezer by anair curtain established by one or more fans which blow air towards oneor more air outlets via a cooling heat exchanger and which recover airin the air curtain via one or more air inlets for recirculation to theone or more air outlets; the kit comprising one or more outlet ducts fordirecting air from the one or more fans towards the cooling heatexchanger such that air blown by the one or more fans is directedtowards the cooling heat exchanger; wherein the one or more outlet ductsare shaped to terminate at the cooling heat exchanger at a first end.

In some embodiments, the one or more outlet ducts are shaped toterminate at the one or more fans at a second end. This may improve airflow from the one or more fans to the cooling heat exchanger.

In accordance with a further aspect of the invention, there is alsoprovided a display refrigerator or freezer which includes features ofboth the first aspect of the invention and the third aspect of theinvention (i.e. which includes both air inlet ducts and outlet ducts).The features indicated as optional in respect of either or both thefirst and third aspects of the invention are also optional in thisfurther aspect of the invention.

Embodiments of the invention will now be described with reference to theaccompanying drawings, in which:

FIG. 1 shows a side cross-section of the bottom portion of a displayrefrigerator according to the first aspect of the invention.

FIG. 2 shows a schematic view of a display refrigerator according to thefirst aspect of the invention from underneath the base shelf of therefrigerator.

FIG. 3 shows a schematic view of the bottom portion of a displayrefrigerator according to the first aspect of the invention from abovethe bottom shelf of the refrigerator.

FIG. 4 shows a side cross-section of the bottom portion of a displayrefrigerator according to the third aspect of the invention.

FIG. 5 shows a schematic view of a display refrigerator according to thethird aspect of the invention from underneath the base shelf of therefrigerator.

FIG. 6 shows a schematic view of the bottom portion of a displayrefrigerator according to the third aspect of the invention from abovethe bottom shelf of the refrigerator.

FIG. 1 shows a side cross-section of the bottom portion of a displayrefrigerator 100. The display refrigerator 100 has a refrigeratedstorage space 102 that is maintained at a lower than ambienttemperature. Within the refrigerated storage space 102, there is a baseshelf 116. Various embodiments may have one, two, three, four, five orany number of additional shelves (not shown) disposed above the baseshelf, which may be flat, may be at an angle or may be mixture of angledand flat shelves. A typical angle for the angled storage shelves is 20°,however shelves at other angles may be used, as long as the productbeing refrigerated does not slide off the shelves. The displayrefrigerator 100 establishes an air curtain 106 by fans 108 within thedisplay refrigerator 100 which blow cold air towards an air outlet (notshown), out of the air outlet to form the air curtain 106, the air fromwhich is recovered by the fans 108 through an air inlet 114. Air inletducts 118 arranged between the air inlet 114 and the fans 108 direct thewarm air recovered through the air inlet 114 towards the fans 108. Theair inlet ducts 118 in combination with a portion of the base shelf 116defines a cavity 120. Air in the cavity 120 is sealed from the warm airrecovered by the air inlet 114. This means that the relatively warm airrecovered by the air inlet 114 is separated from the base shelf 116,thus avoiding warming of the underside of the base shelf 116. This hasthe effect that the refrigerator can operate at a lower power tomaintain a required temperature in the storage space 102, decreasingenergy consumption. Further, the presence of the air inlet 114 causes areduction in the turbulence of the air passing into the fans 108 whichincreases the efficiency of the display refrigerator 100, againdecreasing energy consumption required to maintain the requiredtemperature in the storage space 102. Air directed by the air inletducts 118 to the fans 108 is recirculated by the fans 108 to the airoutlet via a cooling heat exchanger 112 within the display refrigerator100. The cooling heat exchanger 112 maintains the recirculated air (andhence the air blown through the air outlet to form the air curtain 106)at a desired temperature. The desired temperature is chosen to be lowerthan ambient and acts to prevent cold air in the refrigerated storagespace 102 from mixing with warm air exterior to the refrigerator 104.

FIG. 2 shows a schematic view of the same display refrigerator 100 shownin FIG. 1 from underneath the bottom of the display refrigerator 100.FIG. 3 shows a schematic view of the bottom portion of the same displayrefrigerator 100 shown in FIGS. 1 and 2 from above the bottom shelf ofthe refrigerator. These views show the shape of the air inlet ducts 118in more detail.

FIG. 4 shows a side cross-section of the bottom portion of a displayrefrigerator 100. The display refrigerator 100 has a refrigeratedstorage space 102 that is maintained at a lower than ambienttemperature. Within the refrigerated storage space 102, there is a baseshelf 116. Various embodiments may have one, two, three, four, five orany number of additional shelves (not shown) disposed above the baseshelf, which may be flat, may be at an angle or may be mixture of angledand flat shelves. A typical angle for the angled storage shelves is 20°,however shelves at other angles may be used, as long as the productbeing refrigerated does not slide of the shelves. The displayrefrigerator 100 establishes an air curtain 106 by fans 108 within thedisplay refrigerator 100 which blow cold air towards an air outlet (notshown), out of the air outlet to form the air curtain 106, the air fromwhich is recovered by the fans 108 through an air inlet 114. Fans 108within the display refrigerator 100 recirculate the warm air recoveredthrough the air inlet 114 to the air outlet via a cooling heat exchanger112. Outlet ducts 122 arranged between the fans 108 and the cooling heatexchanger 112 ensure that air blown by the fans 108 is directed towardsthe cooling heat exchanger 112. This ensures that air passes more evenlythrough the cooling heat exchanger 112 which increases the efficiency ofthe display refrigerator 100, decreasing energy consumption.

FIG. 5 shows a schematic view of the same display refrigerator 100 shownin FIG. 4 from underneath the bottom of the display refrigerator 100.FIG. 6 shows a schematic view of the bottom portion of the same displayrefrigerator 100 shown in FIGS. 4 and 5 from above the bottom shelf ofthe refrigerator. These views show the shape of the outlet ducts 122 inmore detail.

It should be understood that although the air inlet ducts and outletducts are shown in separate exemplary figures above, the invention alsoincludes further embodiments where the display refrigerator or freezerincludes both air inlet ducts and outlet ducts.

1. An apparatus, comprising: a housing defining a refrigerated storagespace; an air outlet configured to produce an air curtain that separatesair in the refrigerated storage space from air exterior to the housing;a cooling heat exchanger and which recovers air in the air curtain viaan air inlet such that air can be recirculated to the air outlet; ashelf disposed within the refrigerated storage space; and a ductfluidically coupling the air inlet and the air outlet, at least aportion of the duct and, at least a portion of the shelf defining atleast a portion of a cavity beneath the shelf that is sealed from airrecovered via the air inlet.
 2. The apparatus of claim 1, wherein: theair outlet is from one or more air outlets, the air inlet is from one ormore air inlets, and the duct is from a one or more ducts, the apparatusfurther comprising: one or more fans, each fan from the one or more fansconfigured to blow air towards an air outlet from the one or more airoutlets, the apparatus includes an equal number of ducts from theplurality of ducts and fans from the plurality of fans, each duct fromthe one or more ducts fluidically couples an air inlet from the one ormore air inlets to one fan from the one or more fans.
 3. The apparatusof claim 1, wherein the cavity is evacuated.
 4. The apparatus of claim1, wherein the duct is an air inlet duct, the apparatus furthercomprising: a fan configured to blow air towards the air outlet; and anoutlet duct disposed between the fan and the cooling heat exchanger suchthat air blown by the fan is directed towards the cooling heatexchanger.
 5. The apparatus of claim 4, wherein the cavity is defined atleast in part by a portion of the outlet duct.
 6. The displayrefrigerator or freezer of claim 1, wherein the cavity is defined atleast in part by insulation material. 7.-8. (canceled)
 9. An apparatus,comprising: a housing defining a refrigerated storage space; a coolingheat exchanger; a fan configured to blow air towards an air outlet viathe cooling heat exchanger to form an air curtain that separates therefrigerated storage space from air exterior to the housing, the coolingheat exchanger configured to recover air in the air curtain via an airinlet for recirculation to the air outlet; and a duct arranged betweenthe fan and the cooling heat exchanger such that air blown by the fan isdirected towards the cooling heat exchanger.
 10. The apparatus of claim9, wherein: the duct is from one or more ducts and the fan is from oneor more fans; the apparatus includes the same number of ducts and fans;and each duct from the one or more ducts is arranged to direct air toone fan from the one or more fans.
 11. A method of modifying a displayrefrigerator or freezer, wherein the display refrigerator or freezerincludes a refrigerated storage space, air in the refrigerated storagespace being separated from air exterior to the display refrigerator orfreezer by an air curtain established by one or more fans which blow airtowards one or more air outlets via a cooling heat exchanger, thecooling heat exchanger configured to recover air in the air curtain viaone or more air inlets for recirculation to the one or more air outlets,the refrigerated storage space having a base shelf, the methodcomprising: arranging one or more air inlet ducts between the one ormore air inlets and the one or more fans such that the air recovered viathe one or more air inlets is directed by the one or more air inletducts towards the one or more fans such that the one or more air inletducts, in combination with at least a portion of the base shelf, defineat least a portion of a cavity beneath the base shelf, the cavity beingsealed from the air recovered via the one or more air inlets.
 12. Themethod of claim 11, further comprising arranging the same number of airinlet ducts between the air inlets and the fans as the number of fanssuch that each air inlet duct from the one or more air inlet ducts isconfigured to direct air to one fan from the one or more fans.
 13. Themethod of claim 11, further comprising evacuating the cavity.
 14. Themethod of claim 11, further comprising arranging one or more outletducts between the one or more fans and the cooling heat exchanger suchthat air blown by the one or more fans is directed towards the coolingheat exchanger.
 15. The method of claim 14, further comprising arrangingthe one or more outlet ducts such that the cavity is defined at least inpart by a portion of the one or more outlet ducts. 16.-19. (canceled)